58 patients with acute LBP and severe disability with an Oswestry Disability Index(ODI) of 60% or higher were randomly allocated and divided into 2 groups. The experimental group was treated with MSAT and the control group was treated with intramuscular injections of diclofenac(NSAID). All administrations were limited to 1 session, and comparisons were made of measurements before and after treatment. Primary outcomes were measured by the NRS(numerical rating scale) of back pain in active movement. Secondary outcomes were measured by the NRS of radiating pain, ODI scores, and the patient's global impression of change(PGIC) etc. Post-treatment follow-up will be performed to measure primary and secondary outcomes with the exception of ROM and SLR at 2, 4, and 24 weeks after treatment.